1. Field of the Invention
The present invention relates generally to aviation safety systems, and particularly to a ground-based recovery system for aircraft with disabled landing gear.
2. Description of the Related Art
Relatively high speed aircraft generally incorporate retractable landing gear in order to reduce aerodynamic drag and to increase efficiency and fuel economy in flight. While this is primarily true of airplanes, i.e., fixed wing powered aircraft, it is also true of higher performance helicopters, and even many types of gliders or sailplanes insofar as increasing aerodynamic efficiency is concerned.
The designers and manufacturers of aircraft with such retractable landing gear systems endeavor to design and construct such systems to have the highest practical reliability. Nevertheless, the occasional landing gear system failure can and will occur with such aircraft. This may be due to any of a number of causes, such as depletion of hydraulic fluid due to a leak, a mechanical component becoming disconnected or jammed by foreign matter, etc. In such instances, the flight crew of the aircraft has no alternative but to land the aircraft with the landing gear retracted, assuming that it has not locked or jammed at some intermediate position. Such potential occurrences have been planned for at all certified air carrier airports, so that firefighting vehicles are on hand that are capable of deploying foam on a runway to reduce the chance of fire during or after the wheels-up landing.
Nevertheless, landing a retractable gear aircraft with the landing wheels retracted is still a risky operation. The larger and heavier the aircraft and the number of passengers being carried and the greater the landing speed, the greater chance there is of significant damage to the aircraft and/or injury to passengers. Even in the event of a successful wheels-up landing by a large air carrier aircraft, there will be significant damage to the aircraft structure due to the significantly greater forces and speeds encountered during such a landing. Such damage may well result in repair costs greater than the value of the aircraft, even when the obvious external damage to aircraft skin panels does not initially appear to be great.
Accordingly, a number of ground-based systems for recovering a retractable landing gear aircraft with wheels retracted have been developed in the past. An example of such is found in German Patent Publication No. 4102271 published on Jul. 30, 1992 to Airbus GMBH et al. This reference describes (according to the drawings and English abstract) a ground-based system for launching and recovering compatibly configured aircraft devoid of landing gear as a normal operation.
German Patent No. 19950674, published on Apr. 26, 2001, describes (according to the drawings and English abstract) a mobile landing surface that is accelerated to substantially match the landing speed of the aircraft using the mobile surface. The mobile surface is installed atop a conventional fixed runway to travel therealong as needed for the recovery of an aircraft. Various speed sensing devices, pads, cushions, and shock absorption devices are included on the mobile platform.
German Patent No. 102007052277, published on Nov. 5, 2009, describes (according to the drawings and English abstract) a method for landing an aircraft with fully or partially retracted landing gear. An emergency carriage is provided with backup systems. The carriage may be an autonomous, motorized, remotely controlled device.
Thus, a ground-based recovery system for aircraft with disabled landing gear solving the aforementioned problems is desired.